For centuries the use of hair coloring was restricted to the fashion needs of a privileged few and was dictated by necessity to hide gray hair. Today a lot of people, both women and man, use hair coloring to change their appearance. There are several reasons for this: to hide white hair, to lighten hair color and add additional highlights, to remove the yellow look from grey hair, enhance natural color, etc.
From a technical standpoint, extensive laboratory and research work is essential because of the diverse problems to be solved. The indiscriminate use of certain colorants may have dermatological and toxicological side effects. It is well known that hair dyes are subject for large studies in the field of allergology. Specific classes of dyes like direct and oxidative dyes, also known as Paraphenilene Diamine dyes, are known allergens and suspected carcinogens and genotoxins. (Charles Zviak, The Science of Hair Care, Marcel Dekker, 1986, p.235-240).
Although hair coloring using natural dyes is mentioned in most ancient documents, the development of new natural plant based hypoallergenic hair coloring systems remains a scientific and technological challenge. Most common are hair dye compositions based on henna. According to Zviak, henna is a natural product and generally does not have any side effects. The henna leaves are dried and crushed into powder and applied as a paste with hot water. Henna is typically produces auburn and brown-orange colors. However, henna does have a number of major drawbacks, such as complicated preparation and application, unleveled shades, incompatibility with other hair dyes and treatments, etc. Therefore, henna was almost completely replaced with synthetic hair dyes.
Recently henna has been regarded as a “back to nature” alternative for home use and by many hairdressers.
As early as 1907 improvements in henna dyes were attempted and were based on hair lacquers using phenol compounds such as pyrogallol and nickel, iron, copper, cobalt, or lead salts in the presence of reducing salt and a medium containing henna. These compounds produced full range of colors.
However, the disadvantages of hair dyes containing metallic salts are numerous. Most of them are toxic to some extent, and their use is strictly regulated. They nearly always create a dull, leaden color with a flat metallic appearance. Moreover, the metal fixed on the hair shaft acts as a catalyst, causing an abrupt breakdown of the hydrogen peroxide in bleaching products or permanent wave fixers resulting in significant hair damage
(C. Zviak, p. 241). Compounded henna remains the only natural alternative to conventional hair color.
Therefore, development of new non-toxic natural hypoallergenic alternatives to conventional hair color remains a scientific and technological challenge. Discovery of mild, non-toxic ingredients for compounded henna compositions can theoretically solve problems of color appearance, toxicity, application, and compatibility with other treatments.
The patent literature describes the enhancement of conventional oxidative dye composition with henna (or enhancement of so-called black henna). In U.S. Pat. No. 6,139,853, the solid hair colorant composition described comprises a 10-35% p-phenilenediamine based oxidative formula also containing non-oxidative dyes like HC Blue 2 and HC Yellow 12 and 25-70% neutral henna. While the disclosed colorant contains henna and is more convenient to use in comparison to regular henna, it still contains p-phenilenediamine that is not suitable for people with allergic reactions to p-phenilenediamine.
A similar composition, described in US 20060010618, discloses Myristine Africana plant parts used in an oxidative (p-phenilenediamine) based formula.
DE4402203 describes hair dyeing compositions containing ginseng and plant based dye as a temporary color.
JP4013611 A2 describes a hair coloring composition based on freeze-dried plants such as Acacia Shikouka and mordanting metals like Fe, Cr, Mn, or Sn.
JP2872385 B2 describes combination of oxidative dyeing agent, vegetable dyeing agent and quaternary ammonium salt.
A similar composition is described in U.S. Pat. No. 4,183,366 where 75-95% henna powder is mixed with non-ionic surfactant and 0.5-5.0 of a quaternary salt. Both patents describe a more convenient application procedure. However, there is no mention of durability and/or coloring palette improvement.
DE4201749 A1 describes compositions utilizing Alkanna root but only for graphite gray color.
DE19600225 A1 describes hair dyeing compositions based on utilization of oils and liquid waxes in a mixture of natural and synthetic dyes.
WO2007130777 A3 describes a composition of Acid Blue 74 and Mordant Red11 and combination of encapsulated mordant and natural dye extract. This composition does not seem to be practical due to low core payload possible because of the encapsulation technique.
US20030145395 describes hairdressing compositions of henna, tannin, catechin, gardenia, lac, annatto, brazilin and turmeric based pigments providing wide range of colors. However, the mordants described in this patent, like white lead and antimony white, can possess toxicological risks. Also, the scalp staining is the probable cause of using titanium and zinc oxides to inhibit the coloring process.
U.S. Pat. No. 7,186,279 describes a black dye comprising of Juglas Regia, Indigofera Tinktoria, Acacia Accocina, Lawsonia Interims, and hair coloring mordant based on natural tannins. While the composition is described as nontoxic and safe, it results in only one color—black, which is not practical for the modern hair coloring industry.
The use of mordants is well known in the leather and textile industry and has been employed for centuries as a vegetable dye coloring method. However, the use of mordants has been limited in recent years because of their generally high toxicity. The most common mordants are salts of chromium and are still used in the leather industry, although rarely. Other mordants include salts of aluminum and copper which also possess both toxicological and environmental concern (Joseph Rivlin, The Dyeing of Textile Fibers, PCT&S, Philadelphia, 1992, p. 30-52, H.S. Freeman & A.T. Peters, Colorants for Non-Textile Applications, Elsevier, 2000, pp. 382-449) but are still in use in some textile and leather applications.
The mordant's function is to form a complex between a polyvalent metal salt and a dye. The application of a mordant traditionally requires at least two steps and often includes a pre- or post treatment as well. The reaction between mordants and dyes is virtually instantaneous, making it necessary to apply them separately. This is a significant disadvantage of the mordanting technique because scalp staining can occur due to the fast reaction between mordant and dye.
A desirable quality to incorporate into a mordant-dye system for coloring human hair would be to provide time delay in this reaction for several reasons. First, to decrease scalp staining which occurs during the instantaneous reaction between dye and mordant on both scalp and hair. Second, to make the system more convenient and give stylist or home user an opportunity to adjust the color and its depth. Third, to save time and make this application as convenient as a regular hair coloring process.
Copper sulfate has been known as a mordant for centuries. Its limitations of application in industries like textiles are limited due to harmful ecological effects (Rivlin p. 108-109) and toxicity. For the same reasons, copper sulfate did not find applicable use in hair coloring applications. However, copper based or mordanted dye compositions applied on textiles exhibit valuable qualities like broad range of colors, light and weather fastness and durability of color (Rivlin p. 108-109).
However, some copper salts such as lactic, acetic, tartaric, succinic and gluconic acids, in particular ones made from renewable plant based sources, are not only considered to be non-toxic but are also used as a dietary and food supplements. Copper is involved in numerous biochemical reactions in human cells and is a component of multiple enzymes, is involved with the regulation of gene expression, mitochondrial function/cellular metabolism, connective tissue formation, as well as the absorption, storage, and metabolism of iron.
Copper levels are tightly regulated in the body. Copper deficiency can occur in infants fed only cow-milk formulas (which are relatively low in copper content), premature/low-birth weight infants and in adults causing cystic fibrosis. Medicinal use of copper compounds dates to Hippocrates in 400 B.C. Bacterial growth is inhibited on copper's surface, and hospitals historically installed copper-alloy doorknobs and push-panels as a measure to prevent transmission of infectious disease. (Paul Coates et al., Encyclopedia of Dietary Supplements, 2005, Marcel Decker, pp.133-141).
The direct application of copper salts of lactic, acetic, tartaric, maleic, glycinic, succinic and gluconic acids in natural henna based compounding is not found in the art.
U.S. Pat. No. 7,087,255 discloses copper salts application in chewing gums as a dietary supplement, in particular copper gluconates and lactates. Copper Gluconate is disclosed as a suntan accelerator and skin protectant during sun tanning (U.S. Pat. No. 5,075,102). Similar application is described in U.S. Pat. No. 5,698,184. Copper Gluconate was proposed to increase melagenesis (darkening of skin and hair) as a part of sun tanning composition as an alternative to DHA (U.S. Pat. No. 6,696,417). U.S. Pat. No. 6,428,580 describes use of Copper Gluconate as a part of oxidizing system for perms.
Hair dyes known as dry henna (compounded henna) contain metallic salts in order to provide a right color. Most salts are heavy metals. Most of them are toxic to some extent, and their use is strictly regulated. Compounded henna nearly always creates a dull, leaden color with a flat metallic appearance. Despite all the detriments, compounded henna remains to be the only natural alternative to conventional hair color.
U.S. Pat. No. 7,550,014 entitles “Composition for dyeing keratin fibers and a method of dyeing hair using same” is limited to encapsulation and one part system only.
Copper Gluconate is mentioned but it is known that encapsulation of water soluble salts is very difficult and in many cases impractical. The maximum theoretical payload of encapsulated material can be no more than 10%.
Active copper content in Copper Gluconate can not be more than 12.4% based on molecular weight. In order to achieve concentrations mentioned in this patent (0.01-5%) the disclosed formula has to contain 620% of Copper Gluconate encapsulated to obtain 5% of active copper. It is impossible since maximum concentration of ingredients in formula can be only 100%. At 50% of encapsulate in formula there is 0.4% of active copper and there is not enough room for other ingredients, i.e. water as it is known that aqueous dyes can not produce color without sufficient water.
At 5% of encapsulate in the formula of this patents composition, the composition can deliver only 0.04% of active copper. At this concentration, color can not be developed due to very low concentration of mordant, i.e. Copper Gluconate. Practical concentrations around 0.5-5% of active copper cannot be achieved by encapsulation techniques.
Therefore, development of a non-toxic natural hypoallergenic alternative to conventional hair color which does not exhibit these detrimental effects remains a scientific and technological challenge and it is an object of this invention to provide a hypoallergenic alternative to conventional hair color which does not exhibit these detrimental effects.
Therefore, it is an object of this disclosure to provide final products that can be made using 100% Green Chemistry.
It is an object of this disclosure to provide final products that do not utilize encapsulation.
It is an object of this disclosure to provide new, effective and non-toxic compounded henna based hair dyes.